Insulator.



W. T. GODDARD.

NSULATOR.

N FILED APR. 4, 1916.

Patented July 3, 1917.

APPL! WALTER T. GODDABD,'OF HAMILTON, ONTARIO, CANADA.

INSUL ATOR.

Specification of Letters Patent.

Patented July 3, 1917.

Applieatioiifled April 4, 1916. Serial N o. 88,812.

To all whom t may concern.'

Be it known that I, W.-\LTEn TMGODDARD, of Hamilton, Province of Ontarioaand Dominion of Canada, have invented certain new and useful Improvements in Insulators; and I do hereby declare the following to be a full, clear, and exact description `of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon. l

My invention relates to insulators,` and more particularly to what are known as strain insulators employed for supporting high tension conductors, and embodying generally a pair of metal strain members separated by an insulating member to which they are connected, and the chief purpose of my improvement is to afford such a connection or joint between the insulating and strain members as will entirely eliminate any disturbance in the insulating material resulting from the difference between the coefficient of expansion of the insulatin 'material and that of the metal strain member. A further purpose of the invention is to afford a strong and rigid structure which can be manufactured simply and at a reasonable cost, while at the same time having the facility for withstanding any strains to which an insulator of this type is ordinarily subjected. Further, the invention consists in so constructing a metallic strain member and so uniting it with the insulating member, that the metal of the strain member will have no serious or bad effect upon the material of the insulating member, such as cracking or breaking it upon changes in temperature conditions. To these and other ends the invention consists in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end o. the specification.

In the drawings:

Figure l is a sectional view illustrating the application of the improvement to a well known type of insulator;

Fig. 2 is a View in elevation of the strain member, and

Fig. 3 is a horizontal sectional View line 3&31 of F ig. l.

Similar, reference numerals throughout the several Views indicate the same i rts.

In the illustratedembodimento 'thein -member in the form of a expansion or contraction of the vention, ythere is shown an insulator which includes an insulating section or member and comprising a l at the bottom of stance of like character, central or upper portion which is formed the downwardly and out- Y wardly flaring portion or skirt 2. Attached to the upper portion l is an upper strain cap 3 which may be secured to the insulating member by cementing material 4. A

The insulating memb'er is provided with an interior or hollow portion to receive a `lower metallic strain member which embodies a hollow body portion 5 split on opposite sides thereof as designated by 6 to afford a plurality of sections or arms or yieldable walls 7. (The body portion 5 of the strain member is stamped to form a screw thread, both interiorly and eXteriorly, and arranged within the interior of the strain member is a. fill-er preferably in the form of a block composed of porcelain or some other substance having substantially the same coeflicient of expansion as that of the material of which the insulating member is constructed.I The block or filler referred to is designated by 8, and is preferably threaded for engagement with the thread on the inner wall of the strain member. The latter is held in position within tween the walls ofthe strain member and of the insulating member, also filling the space formed by the slots or cuts 6 in the strain member. The latter also embraces a lower portion or lug l0 having an opening l1 by which it may be connected to the cooperating strain member of the adjacent insulator unit. By reason of the thinness of the Wall of the metal strain member which is secured to the insulating member, the expansion and contraction of said wall becomes a negligible factor, as it is not sufficient to harm or seriously injure the insulating material in an way. This result is further assisted by the openings or spaces 6 between adjacent edgesv of the arms or sections on t-he strain member, which are thereby permitted a slight expansion in the direction of the wall, and to this'eXtent preventing the transverse eX- pansion that would otherwise take place. The net result is that the metal of the strain member ma expand or contract within or'- dinary limits without transmitting such etl'ect to the insulating member to an extent that is noticeable, and the porcelain or other composition of the insulating member is protected against breaking or cracking such as is liable to take place when a solid metal strain pin is employed. At the same time, the necessary strength is imparted to the structure by means of the block arranged within the strain member, and serving to hold the walls thereof rigidly so as to withstand the same strains that a solid metallic pin would under like circumstances. The

tiller or block within the strain member be: ing of porcelain or other material possessing the same coeicient of expansion as the in- I sulating member, will always expand and having a hollow portion with yieldable walls extending within the insulating member and lsecured thereto by a cementitious medium,

and a block of illing material arranged with the hollow portion'of the strain member and composed of a substance having substantially the same coeicient of expansion as the insulating member. 2. The combination with a hollow insulating member, of a metal strain member having an interiorly threaded hollow portionextending within the insulating member v and secured thereto by a cementitious medium, and a block having threaded engagemeaars ment with the interior of the hollow portion of said strain member and composed of a substance having substantially the same c0- e)iicientr of expansion as the insulating mem- 3. The combination with a hollow insulating member, of a metal strain member having a hollow portion which is'threaded interiorly and split to aiord yieldable walls, a cementitious binder between the hollow portion of the strain member and the insulating member, and a block threaded within said hollow portion of the strain member and composed of a substance having substantially the same coeicient of expansion as the insulating member.

4. The combination with a hollow insulating member. of a metal strain member having a plurality of sections or arms in spaced relation to each other and extending within the insulating member, a block within the interior space defined by said sections, having engagement with the sections, and composed of a substance having substantially the same coeiiicient of expansion as the insulating member, and a cementitious binder between said sections and the insulating member.

5. The combination with a hollow insulating member, of a metal strain member having a hollow portion formed by a pair of semi-circular sections threaded interiorly, a filling block in threaded engagement with the interior of said sections and composed of a substance having substantially the same coefficient of expansion as the insulating member, and a cementitious binder between said sections and the insulating member.

VALTER T. GODDARD. 'lVitnesses J. N. SAUNDERS, EDWARD A. FOLEY. 

